1. Field of the Invention
The present invention relates to a cue stick. Particularly, it relates to a cue stick having a solid force-transmitting pipe and a wooden fitting portion. In which, the weight and size are nearly same as the ones of a traditional solid wood cue stick. The total weight of the cue stick is proper. Its internal force transmission is evenly distributed. Plus, the feedback feeling for striking the cue ball is excellent.
2. Description of the Prior Art
FIG. 1 is an exploded view showing a first traditional cue stick 70. It includes a shaft 71 and a butt 72. This shaft 71 contains a thread hole 711. The butt 72 has a threaded portion 721. So, the shaft 71 and the butt 72 can be connected together as a long stick. Because the shaft 71 and the butt 72 are made by wood, there are many tiny internal gaps and spaces (not shown) in the wood. When a player uses a brand new cue stick 70, by repeated striking the cue balls, the internal gaps and spaces of this cue stick 70 will be compressed gradually. After using a period of time, most internal gaps and spaces are compressed into a stable condition (almost reaching its limit and it cannot be compressed anymore). Under such circumstances, when the player strikes the cue ball, this person has a feeling of consistency. The feeling of consistency can be explained and defined as below. Assuming the hand of this player applies a hitting force of 100 units. The cue stick 70 only absorbs 1 to 2 units. So, the force transmitted to the cue ball is very close to the ideal condition. At this moment, the control for striking a cue ball is accurate and stable. However, based on the experiences of most professional players, it usually needs several weeks or even several months to obtain such feeling (that is the feeling of consistency) depending on different players and different cue stick materials. However, if a buyer has to spend such a long period of time to obtain the feeling of consistency for a new cue stick, it takes too much time. It significantly reduces the willing for buying a new cue stick.
In order to reduce the above-mention time, a second traditional cue stick 80 appears in the market of cue sticks. Referring to FIG. 2, the second traditional cue stick 80 comprises a shaft 81 and a butt 82. The shaft 81 has a tip 811, a solid portion 812 (having a first length L1), a hollow portion 813 (having a second length L2) and a connecting portion 814. This hollow portion 813 has a deep hole 815 for receiving a hollow solid force-transmission portion 83. This hollow solid force-transmission portion 83 has an inner cylindrical space 84. When the player applies a hitting force F, this hitting force F passes through both the hollow solid force-transmission portion 83 (indicated by a first component force F1 as shown in FIG. 2) and the hollow portion 813 (indicated by a second component force F2 as shown in FIG. 2) and finally through the solid portion 812 as well as the tip 811. Nevertheless, it still has the following problems and disadvantages.
[1] The balance point of the cur stick moves back. Although the force transmission of the second traditional cue stick 80 is better than the first traditional cue stick 70, the second traditional cue stick 80 contains an inner cylindrical space 842. It makes the weight of the shaft 81 lighter. The balance point of this second traditional cue stick 80 moves back. Because of this change, the holding position has to be changed accordingly. It will influence the feeling of holding the second traditional cue stick 80 that the player has gotten used to. Also, it might cause the hitting force cannot be accurately controlled. Anyway, the striking feeling becomes odd for this player.
[2] The weight of the cue stick becomes lighter. The air fills in the inner cylindrical space 842, so the total weight of the second traditional cue stick 80 becomes lighter. Hence, the inertial force of the second traditional cue stick 80 becomes smaller. It also means the dynamic energy for making the cue ball moving becomes smaller. Therefore, it will cause the moving path shorter (assuming the cue ball should move from the first position P1 to the second position P2, but it only arrives the third position P3, as illustrated in FIG. 3). Besides, it will reduce the rotational energy (while striking with sidespin) so that the moving path deviates (such as the directions V1 or V2 shown by the dotted lined in FIG. 3). Even though it is just a small difference, it could make the player loose the game.
[3] Its force transmission is not evenly distributed. Due to the existence of this inner cylindrical space 842, the force will transmit through the hollow portion 813 and the hollow solid force-transmission portion 83. Therefore, its force transmission is not evenly distributed.